Pioneering NZ study to aid war on rheumatic fever

A first-of-its-kind study could lead to better treatment for a cruel disease affecting kids in our poorest, most over-crowded homes.

January 3, 2018

By: Jamie Morton

Acute rheumatic fever is a complication of a sore throat caused by group A streptococcal bacteria. Photo / File

A first-of-its-kind study could lead to better treatment for a cruel disease affecting kids in our poorest, most over-crowded homes.

Acute rheumatic fever is a complication of a sore throat caused by group A streptococcal bacteria.

An inflammatory response can cause joint pain, or rheumatic heart disease, which scars heart valves and kills about 140 people in New Zealand each year.

The disease is notably associated with poverty and overcrowded housing and the incidence is far higher in New Zealand’s Maori and Pacific populations than in other ethnicities.

But a vaccine against the bacteria infection remains years away.

Until then, the most effective recommended measure involves painful monthly muscle injections of a type of penicillin known as benzathine penicillin G, or BPG, for a decade or longer.

The treatment, also called secondary prophylaxis, aims to prevent infections that may lead to the recurrence of rheumatic fever and either cause or worsen rheumatic heart disease.

But making sure children and young people received their monthly injections was a challenge, Otago University medical researcher Dr Dianne Sika-Paotonu said, and improvements were “urgently needed”.

Despite rheumatic fever’s toll in New Zealand and around the world, there was still only limited data on how the penicillin was working in the people receiving it.

Early studies to determine how BPG might work were conducted in healthy, fit, white, young military recruits aged between 18 and 24 years – none of whom had rheumatic fever or rheumatic heart disease.

In a new two-year study, supported with a $250,000 grant from the Health Research Council, Sika-Paotonu will work with other researchers to look at how exactly BPG has been working in other groups, including Maori and Pacific children.

The researchers were also trying to better understand from families and clinicians how its use might be improved.

Sika-Paotonu said the new insights would help create a more appropriate form of penicillin that was hopefully longer acting, less painful and more effective and suitable for patients.

The team was seeking to recruit people in the Wellington area, aged between 5 and 21 and mainly of Maori and Pacific Island descent, receiving injections for rheumatic fever.

Blood samples would be taken to help the researchers see how much penicillin entered blood circulation, and how long it lasted.

“This type of pharmacology research work would usually require large blood volumes from participants,” Sika-Paotonu said.

“Thanks to research teams in Australia, this work can now be carried out using finger-prick samples instead, which is highly preferable to other methods requiring larger blood volumes in children.”

The research was the first BPG study to focus on young Maori and Pacific Island people. Another study in Australia was targeting indigenous Aboriginal populations suffering acute rheumatic fever.

Collectively, she said, the findings had the potential to influence future medical and public health recommendations, and contribute to global efforts against the disease.

Just a sore throat … too many families now know some sore throats last a lifetime. FIONA CASSIE talks with some of the passionate pioneers of school throat-swabbing campaigns as the national Rheumatic Fever Prevention programme rolls out.